Small Animal Neurologic Diagnosis Flashcards
The goal of a neurological exam is
to understand the functional basis for the nurological disorder
most people only remember about 10% of what you tell them
components of the neurological exam
observation
postural reactions
spinal reflexes
sensation - presence, absence or diminished
cranial nerves
observation
mentation
behavior
posture
gait
mentation
- BAR - bright, alert, responsive
- QAR - quiet, alert, responsive
- QAD - quiet, alert, depressed
- dull (depressed)
- disoriented (headpressing, dementia)
- obtunded (poorly responsive)
- stuporous (sleeps all the time)
- coma (cannot be aroused)
behavior
friendly, calm, sweet anxious nervous, hyperactive manic obsessive, compulsive aggressive dangerous
posture
legs are an equal distance in the sagittal plane pelvis is level pelvis is symmetrical leg length is equal optimal alignment meximal support full mobility
gait
stance phase
swing phase
stride
stance phase
the foot is on the ground
swing phase
foot is in the air
stride
from foot fall to lift off, and back to foot fall
evaluating lameness in dog - watch the head
step forward with bad leg - head goes up - opposite in back legs
posturaal reactions
postural tone
proprioception placing hemistand hopping wheelbarrow
postural extensor tone
tests ability to resist gravity
safe for largest dogs
place palm under paw - push up - they should resist you
flex the limb, 3 leg stance
lateral pelvis tilt suggests weak gluteal
postural extenstion thrust
tests the vestibulospinal pathway
normal animal takes a step forward or back to restore balance
response absent or weak with central vestibular disease
lean dog forward - next response is for dog to step forward
deficient proprioception
tendency to bear weight on dorsal aspect of paw
delay in swing phase of gait
excessive flexion, abduction, adduction
postural sway or ataxia
dog on concrete - dog dragging toes - dorsum
proprioception test
flip paw onto its dorsal surface, rest it on the ground
allow time to correct the malposition
absence of correction - CP deficit
knuckling is a sign of
deficient conscious proprioception
neurologic sign of knuckling - information from limb mechanoreceptors is conveyed in the
dorsal column - medial lemniscus
the axons ascend ipsilateral, synapse in the nucleus gracilis, decussate in the ___ synapse in the ___ and disperse in the __
medulla
thalamus
cortex
ataxia
incoordination
ataxia
incoordination
sway while standing or walking
faster gaits may be relatively normal
primarily carried by spinocerebellar tracts
tested by lateral pull on the tail or push on hip - do they correct or fall over
ataxia
ataxia is a sign of
deficient unconscious proprioception
unconscious proprioception - UCP
maintains posture when sitting, standing, and walking
axons travel int he spinocerebellar tracts
processed in the ipsilateral cerebellum
test for postural sway
clinical sign of UCP
ataxia
conscious proprioception - CP
facilitates complex motor activity (catching a frisbee)
axons travel in the dorsal columns (DCML)
large myelinated fibers
processed in the contralateral cortex
clinical sign of CP
knuckling while stanidng or walking
motor function strength
palpate for tone, symmetry, and depth
weak muscles are
soft or atrophied/flaccid
inhibited muscles have
normal mass but are inactive
facilitated muscles have more activity than
normal (spasm) from summation of impulses or weak antagonists
motor function spasms
hypertonic fibers that spontaneously contract
cause spasm
muscle weakness joint injury UMN disease dehydration electrolyte imbalances
sign of UMN disease
hyper-reflexia
“parents” are not functioning
UMNs originate in the
motor cortex
UMN axons descend in the
corticospinal (pyramidal) tracts
UMNs initiate and maintain
voluntary movement
UMN control the nerve (LMN) that directly control
muscular activity
UMN tell LMN
what to do
LMN tell muscles
what to do
maintain extensor muscle tone, thus supporting the body against gravity - regulate posture
UMN
UMN helps maintain
muscle tone
LMN originate from
the spinal cord
LMN directly innervate
muscles and neuroeffector tissues
Signs of LMN disease
flaccid paresis to paralysis
diminished reflexes
rapid muscle atrophy
loss of sensation in associated dermatome
LMN signs indicate a lesion affecting the spinal segments giving rise to
the nerve root, peripheral nerve, or the muscle
LMN children
not playing
late, mild muscle atrophy
UMN
normal to increased tone
UMN
spastic paresis
UMN
normal to hyperreflexia
UMN
decreased proprioception
decreased nociception
UMN
rapid muscle atrophy
LMN
faccid paresis to paralysis
LMN
hyporeflexia
LMN
loss of sensation in associated dermatome
LMN
local paresthesia or hyperesthesia
LMN
most common site for disc injury in dogs
T12-L1
hyperreflexia
a group of muscles innervated from a single spinal segment
myotome
femoral nerve myotome
L4, 5, 6
L5
obturator nerve myotome
L4, 5, 6
cranial gluteal nerve myotome
L6, 7, S1
caudal gluteal nerve myotome
L7, S1, 2
sciatic nerve myotome
L6,7,S1, 2
pudendal nerve myotome
S1, 2, 3
Myotomes for the pelvic limbs
femoral nerve obturator nerve cranial gluteal nerve caudal gluteal nerve sciatic nerve common peroneal nerve tibial nerve pudendal nerve
myotome - femoral nerve - L4, L5, L6 (canine)
muscles that flex the hip, extend the stifle
iliopsoas, quadriceps, sartorius, iliacus
dogs compensate well for this by using abs to swing them forward
myotome - obturator nerve - L4, L5, L6
muscles that adduct the thigh
myotome - cranial gluteal nerve - L6, L7, S1
muscles that abduct the thigh
myotome - caudal gluteal nerve - L7, S1, S2
muscles that extend the thigh
TFL
piriformis
cranial gluteal
superficial and middle gluteal
caudal gluteal
myotome - sciatic nerve - L6, L7, S1, S2
muscles that flex the stifle and extend the thigh
hamstrings
biceps femoris, semimembranosus, semitendinosus
myotome - peroneal nerve - L6, L7, S1, S2
muscles that flex the hock and extend the digits
sciatic nerve
myotome - tibial nerve - L6, L7, S1, S2
muscles that extend the hock and flex the digits
sciatic nerve
myotome - pudendal nerve - S1, S2, S3
muscles of the perineum
urethral sphincter, anal sphincter, caudal rectal,
urinary incontinence in spayed female
dog gets up and was laying in own urine
adjust their sacrum - doesn’t work then go to drugs, proin cucin
spinal reflexes
tonic neck
cutaneous trunci
patellar
withdrawal
muscle under skin - horse flinches skin when fly on them
cutaneous trunci
tonic neck reflex
should stiffen front legs when lifting head and pressing on shoulder blades
run hemostat down spinal column both sides - will stop panniculus reflex at segment of disc herniation
cutaneous trunci
lesionsof the brachial plexus cause a loss of reflex caudal to C-T1
cutaneous trunci
spinal cord lesions T3-L3 cause a loss of reflex 2 segments caudal and ipsilateral to the lesion
cutaneous trunci
gently pinching the skin - always explain what you’re doing
patellar reflex
patellar ligament/tendon
neurological exam - reflex response scale
0 - no reflex - LMN 1 - diminished; hyporeflexia - LMN 2 - brisk, modulated - normal 3 - increased; hyperreflexia - UMN 4 - increased, prolonged; clonus - UMN